A method for specifying a set of instructions selectable for generation by an instruction generator is disclosed. A class name representative of a class of instructions is identified and concatenated with a unique identifier label, thereby defining a unique singleton meta-mnemonic representative of a set of instructions. The class of instructions and the set of instructions are subsets of the instruction set of the processor. The resulting singleton meta-mnemonic specifies the set of instructions available for selection and generation by the instruction generator.